It has been common for many years to supply in the automobile aftermarket what is commonly known as a seat pad, wherein a back and a seat portion are supported by a fold line, covered with a relatively comfortable fabric and further includes springs, ventilation spaces and the like for presenting a more comfortable cushion, or an additional cushion than that supplied with the automobile. Such aftermarket automobile seats or cushions are intended in some cases to negate the effects of summertime heat and wintertime cold on the driver of the automobile as he enters the automobile after a couple of hours of parking.
Of course, home cushions of similar types have also been provided for use on chairs in the home. Other than therapeutic heating pads for home use, such cushions did not provide the capability for full and integral heating of the seat and back of the user, which was a disadvantage in terms of convenience. More importantly, such items for home use could not provide a portable feature, making the item also usable without significant conversion to automobile or boat use.
As to therapeutic heating pads, they are not designed so that one can sit on them.